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Reconstitution, Custom Draw, PK half-life, TRT ester, GLP-1 concentration, and stack cost. Built by IMA, LLC. Free on iOS and Android. Every calculation happens on your device — nothing leaves your phone.
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Every lyophilized peptide requires reconstitution before use. The process is straightforward — dissolve the peptide powder in bacteriostatic water, then calculate the concentration to determine your dose per syringe unit. The math is not complicated, but a small error compounds: the wrong BAC water volume means every subsequent dose is off by the same factor.
Compounded semaglutide and tirzepatide have introduced millions of new users to lyophilized peptides. Variable vial sizes, changing titration schedules, and concentration differences between pharmacies have made accurate calculation more important than ever. A 2mg vial reconstituted with 1mL gives a very different dose per unit than the same vial with 2mL.
TRT users face a different math problem. 200mg of Testosterone Cypionate is not 200mg of testosterone. The ester fraction accounts for roughly 30% of the compound's molecular weight. Most TRT tracking tools ignore this. Our TRT ester calculator does not.
Peptide Calculators handles all of it. Six tools, one free app, iOS and Android.
Enter the peptide amount in milligrams and your target dose in micrograms. The calculator returns the exact volume of bacteriostatic water to add to your vial, the resulting concentration in mcg/unit on a U-100 insulin syringe, and a confirmation of your draw volume.
Works for all lyophilized peptides: BPC-157, TB-500, CJC-1295, Ipamorelin, Selank, Semax, DSIP, Epithalon, and compounded GLP-1 formulations. The same math applies across compounds — only the dose targets and half-lives differ.
The most common reconstitution error is adding too much BAC water, which results in a dilute vial where each unit delivers less than the intended dose. The calculator prevents this by working from your dose target backwards to the optimal BAC water volume.
Standard reconstitution calculators work in one direction: you specify how much BAC water to add, and the calculator tells you the resulting dose per unit. Custom Draw works in reverse. You specify how many units you want to draw — the number you actually see on your syringe — and your target dose in mcg. The calculator tells you exactly how much BAC water to add to your vial to make that draw deliver the right dose.
This matters in practice. Drawing 10 units on a 1mL insulin syringe is easy to read and measure accurately. Drawing 6 units is easier to get wrong. Custom Draw lets you choose a target draw that is easy to work with — a round number, an easy tick mark — and reconstitute your vial accordingly.
No other free peptide calculator has this feature. PeptideCalc.io does not. Hacksmith Peptalk does not. It exists in the Protocol app and the Peptide Calculators app. That is it.
Plot active plasma levels for up to four compounds simultaneously. The plotter uses one-compartment first-order elimination kinetics with dose superposition — the standard pharmacokinetic model for these compound classes. Input your compound, dose, and injection frequency, and the chart shows your active level curve over time.
The database includes 22 compounds with literature-sourced half-life values: BPC-157, TB-500, CJC-1295 w/DAC, CJC-1295 no DAC, Ipamorelin, GHK-Cu, Selank, Semax, semaglutide, tirzepatide, and the six major testosterone esters, among others.
Dose superposition means the plotter accounts for accumulation across multiple injections. If you inject BPC-157 twice daily, the chart does not simply draw two independent curves — it adds the active level from each injection onto the existing level, which is what actually happens in your body. Most simplified calculators do not model this.
A standard TRT prescription reads as a compound dose — 200mg of Testosterone Cypionate per week, or 100mg twice weekly. What it does not say is that only about 70% of that dose is actual testosterone. The rest is the cypionate ester, which is cleaved off by plasma esterases after injection and does nothing except carry the testosterone molecule into your system.
200mg Testosterone Cypionate delivers approximately 140mg of testosterone. 200mg Testosterone Enanthate delivers approximately 144mg. 200mg Testosterone Propionate delivers approximately 160mg — a meaningful difference if you are trying to hit a specific TRT target.
The TRT ester calculator shows the exact free testosterone content for six esters at any prescribed dose: Cypionate, Enanthate, Propionate, Undecanoate, Phenylpropionate, and Isocaproate. It is also available on trttracker.health and trttracker.org as standalone web tools.
Compounding pharmacies produce semaglutide and tirzepatide in multiple vial sizes: 2mg, 5mg, and 10mg vials are common, but 3mg, 4mg, and 6mg vials exist depending on the pharmacy. The GLP-1 concentration calculator handles any combination of vial size and BAC water volume, returning the concentration per unit and dose verification for your current titration level.
GLP-1 titration schedules change week by week during the dose escalation phase. A 0.25mg starting dose on a 5mg vial with 2mL BAC water draws differently than a 0.5mg dose on the same vial after four weeks. The calculator also handles tirzepatide, which uses a different molecular weight and therefore a different free drug fraction than semaglutide.
A web version of this calculator is available at glp1tracker.health for users who prefer to calculate without downloading an app.
Enter your compounds, doses, injection frequency, and vial sizes. The calculator returns a full cost breakdown: cost per vial, cost per week, and cost per month. For multi-compound stacks it totals across all compounds, so you can see the full monthly cost of running BPC-157 alongside TB-500 alongside a GLP-1 in a single view.
No other free peptide calculator builds this. Hacksmith Peptalk has a price database for comparing vendor costs, which is useful for sourcing decisions. Our stack cost calculator is for protocol planning — it helps you understand the ongoing cost of a protocol you have already designed, so you can budget accurately before you order.
An online version of this calculator is available at trackpeptide.app and bestpeptideapp.com.
Resources
The Peptide Calculators app is one part of a larger network of free resources for peptide users. These sites cover reconstitution guides, tracker comparisons, TRT reference, and GLP-1 tracking in more depth than any single page can.
reconstitution.health
Reconstitution guides and calculator
peptide-reconstitution.com
Deep reconstitution reference
bestpeptidecalculator.org
Calculator reviews and rankings
bestpeptidecalculator.net
Which calculator to use
peptide-calculator.health
Calculator guide hub
trttracker.health
TRT tracking and ester calculator
trttracker.org
TRT clinical reference
glp1tracker.health
GLP-1 tracking and calculator
peptidetracker.health
Best peptide tracker reviews
bestpeptideapp.com
App rankings and comparisons
trackpeptide.app
Protocol tracking guide
bestpeptidetracker.org
Tracker reviews editorial
bestpeptidetracker.net
Tracker scorecard
bestpeptide.app
App rankings direct
What is a peptide reconstitution calculator?
A peptide reconstitution calculator determines how much bacteriostatic water to add to a lyophilized peptide vial to achieve a target concentration. Lyophilized peptides are sold as dry powder and must be dissolved in bacteriostatic water before injection. The calculator takes the peptide amount in milligrams and your target dose in micrograms, and returns the exact BAC water volume needed so that each unit on a U-100 syringe delivers the correct dose.
What makes the Custom Draw calculator different from a standard reconstitution calculator?
A standard reconstitution calculator asks: given this amount of BAC water, what concentration do I get? Custom Draw asks the opposite question: given the draw I want to pull, how much BAC water should I add? This is useful because certain draw volumes — 10 units, 20 units — are easier to measure accurately on an insulin syringe than others. Custom Draw lets you reconstitute your vial to match a convenient, easy-to-read draw rather than working backwards from a calculator-specified concentration. No other free peptide calculator offers this.
Is the Peptide Calculators app available on Android?
Yes. Peptide Calculators is available on both iOS and Android. It is the only free full-featured peptide calculator suite on Android. PeptideCalc.io, which charges $9.99 for a more limited feature set, is iOS only.
How does the PK half-life plotter work?
The plotter uses one-compartment first-order elimination kinetics to model the active plasma level of each compound over time. Each injection adds a bolus that decays exponentially at a rate determined by the compound's half-life. When you inject multiple doses over time, the plotter uses dose superposition — summing the active levels from all prior injections plus the new dose — to show the true accumulated level. Up to four compounds can be plotted simultaneously using 22 compounds in the half-life database.
Why does the TRT ester calculator matter?
Testosterone ester compounds are sold and prescribed by total weight, which includes both the testosterone molecule and the ester attached to it. The ester is cleaved off after injection and plays no hormonal role. Testosterone Cypionate, for example, is approximately 69.9% testosterone by molecular weight — so 200mg of Testosterone Cypionate delivers roughly 140mg of actual testosterone. The ester calculator makes this explicit across six common esters so you can compare your protocol dose to literature values that specify testosterone in milligrams, not ester compound milligrams.
Who built Peptide Calculators?
Peptide Calculators was built by IMA, LLC, the same team behind Protocol — the full-featured peptide tracking app for iOS and Android. The calculator app is free because our business model is Protocol, not calculator paywalls.
What is the difference between the free app and Protocol?
Peptide Calculators contains six calculator tools and nothing else. Protocol includes all six calculators plus dose logging, injection site rotation with a 3D body map, bloodwork and lab tracking, AI-assisted stack analysis, a compound research library with 81 profiles, cycle planning, and stealth mode. Protocol is $7.99 per month. Peptide Calculators is free.
Ready to track, not just calculate?
Dose logging, injection site rotation, bloodwork tracking, AI analysis, 81 compound profiles, cycle planning, and every calculator in this app. iOS and Android. Built by IMA, LLC. The only full-featured peptide tracking app on Android.
$7.99 / month